How Does Video Encoding Work?

[00:00] video encoding plays an important part

[00:02] in live streaming it's the process of

[00:04] converting a raw video signal from a

[00:06] camera into a compressed digital format

[00:09] for efficient delivery across the

[00:11] internet the encoder might be integrated

[00:13] directly into a camera or even take the

[00:16] form of computer software or a mobile

[00:19] app

[00:19] often the encoder as a studio tool is

[00:22] used to both apply a codec that

[00:24] compresses the video signal and

[00:26] implement a protocol to transport that

[00:28] stream over the internet

[00:30] while this process often includes audio

[00:33] and video encoding we'll focus on the

[00:35] video aspect for simplicity

[00:37] codec is short for compress decompress

[00:40] when it comes to video there's a ton of

[00:42] information contained in just one second

[00:44] so in order for data to be transferred

[00:46] the stream of video needs to be tightly

[00:48] compressed different codecs achieve this

[00:51] in different ways but most codecs remove

[00:53] information to make the bitrate small

[00:55] enough for live streaming

[00:57] visual algorithms are used to eliminate

[01:00] data that'll go unnoticed by the human

[01:02] eye and motion compensation techniques

[01:04] are used to reduce redundant data

[01:06] between frames

[01:08] once the video has been compressed to a

[01:09] suitable bitrate for the available

[01:11] bandwidth it's streamed using a protocol

[01:14] these streaming protocols take the data

[01:17] and reorganize it as needed breaking it

[01:19] up into optimized chunks for delivery

[01:22] some streaming protocols employ

[01:23] standards used by computer networks they

[01:25] do error checking to ensure nothing gets

[01:28] lost or placed in the wrong order and

[01:30] other protocols use standards made for

[01:33] servers and clients they apply more

[01:35] modern methods used by browsers today

[01:38] when the live video stream reaches its

[01:40] final destination for playback the

[01:41] receiving device unpacks the protocol

[01:44] and then decompresses the codec if the

[01:46] device can't do one or the other then it

[01:48] won't be able to play back the stream

[01:50] now when it comes to codecs h.264 also

[01:53] known as avc is most widely used that's

[01:57] because it's been around for so long

[01:59] most devices can play it back

[02:01] the newer h.265 also known as hevc

[02:06] works better for compressing higher

[02:07] resolutions but royalty concerns have

[02:10] limited its adoption by devices

[02:12] vp9 is royalty free and works great for

[02:15] 4k streaming so it's gaining more

[02:17] traction into devices but av1 is the

[02:21] most current and highly optimized open

[02:24] source option

[02:25] however it does require more processing

[02:27] power to get the job done

[02:29] when picking the right codec you still

[02:31] need to consider the protocol encoder

[02:33] software is mainly designed to stream

[02:35] rtmp but from the prior list rtmp can

[02:39] only handle h.264

[02:41] that's why more encoding software now

[02:43] supports srt which can handle noisy

[02:46] networks better and is codec agnostic so

[02:49] any codec can be used

[02:51] both rtmp and srt are generally not used

[02:54] for playback so that's where a streaming

[02:57] platform like wires of streaming cloud

[02:58] comes in it can take the original stream

[03:01] and repackage it into different playback

[03:03] protocols now this might be hls which

[03:06] supports both h.264 and h.265 or

[03:11] mpeg-dash which like srt is codec

[03:14] agnostic

[03:15] or even webrtc which handles h.264 and

[03:20] vp9

[03:21] av1 support is also on the horizon

[03:24] alright so that's it for how video

[03:26] encoding works in the world of live

[03:28] streaming if you'd like to learn more to

[03:30] help pick the right codecs and protocols

[03:32] for your live streaming needs please

[03:34] contact us at wowza